Can simultaneous perineal sonography and urethrocystometry help explain urethral pressure variations?

To correlate urodynamic with perineal sonographic findings in pressure variations.

In 15 women presenting with urethral pressure variations a urodynamic evaluation with water filling cystometry, urethral pressure at rest and during coughing and uroflowmetry were performed. During water filling cystometry, there were simultaneous perineal video-sonography and urethrocystometry. Video ultrasound images and urodynamic curves were simultaneously monitored on a computer screen.

Simultaneous ultrasound and urodynamic evaluation in the 15 patients revealed movements in two areas leading to urethral pressure variations: activity of the pelvic floor muscles and of the urethral sphincter muscles. For the pelvic floor, we found either slow or fast contractions with, respectively, slow (15-30 cm H2O for 3-10 sec) or fast (30-130 cm H2O for 1-3 sec) urethral pressure changes. Urethral sphincter contractions were always fast, resulting in fast pressure changes of 30-170 cm H2O for 1-3 sec.

Evaluation of simultaneous perineal sonography and urethrocystometry shows the association of urethral pressure variations and muscle activity. Urethral pressure variations are caused by the activity of urethral sphincter or pelvic floor muscles. With ultrasound the activity of the urethral sphincter muscle can directly be seen whereas pelvic floor muscle activity is indirectly visible. Pelvic floor muscle contractions are either fast or slow, whereas the urethral sphincter muscle contractions are always fast contractions.